The present invention relates to a swing-away pet door apparatus for use with a new or existing sliding glass door assembly. The pet door apparatus has a swing-away frame member which is hingedly connected to the door frame. A pet access door is mounted within the swing-away frame. The swing-away pet door apparatus provides ingress and egress through the pet door when the swing-away frame is positioned to abut the sliding glass door frame. For human egress and ingress, the swing-away pet door apparatus is hingedly rotated adjacent to the door frame between open and closed positions. In the open position, substantially full access is provided through the door frame when the sliding glass door is opened in a conventional manner, while allowing the sliding glass door to fully close and lock when the swing away frame is rotated out of the way. When the swing-away pet door frame is positioned to abut the sliding glass door frame, the swing-away pet door apparatus is accessible to the pet for ingress and egress.